GRANBURY, Texas Six people were dead and seven missing after a powerful tornado ripped through a north Texas neighborhood that included housing for the poor, in the deadliest severe storm outbreak in the United States this year.

Authorities were assessing damage and searching through rubble on Thursday, hoping to find survivors among the twisted metal and splintered wood of flattened homes.

"This tornado was a monster," said Hood County Commissioner Steve Berry. "It's just devastating."

The tornado, which brought winds of 166 to 200 miles per hour, was rated an EF4 by the National Weather Service (NWS), the second-most powerful level for such a storm, said NWS meteorologist Mark Wiley. EF4 tornadoes are rare and can blow away a well constructed wood or brick home, according to weather service ratings.

The storm blew homes from their foundations, tossed cars through the air and uprooted trees as it raged through at least four counties near the Dallas-Fort Worth area Wednesday evening.

The National Weather Service said there were reports of 10 tornadoes touching down in the area.

Granbury, a town of 8,000 people about 35 miles southwest of Dallas-Fort Worth, took the hardest hit.

Officials counted four men and two women dead in Hood County, where Granbury is located, said Tye Bell, a county spokesman. Another seven were missing and at least 45 people were injured, many of whom lived in Granbury's Rancho Brazos subdivision of about 110 mostly single-family homes.

Authorities said 17 mobile homes in Granbury were destroyed, while 19 houses were destroyed, 17 suffered major damage and 30 received minor damage.

In Cleburne, about 30 miles east of Granbury, Mayor Scott Cain said more than 600 homes were damaged, with about 30 of them now unlivable.

"People in Cleburne heed the warnings to take shelter and we really believed that saved lives," he said.

HID IN CLOSET

Ronna Cotten, 38, was home with three of her four children when the sirens went off. She and the children, ages 14, 12 and 8, hid in a hallway closet as the twister ripped the roof off their home. When she emerged with her children after the storm passed, Cotten saw "bodies everywhere," she said.

"We're trying to figure out what to do one step at a time," she said.

Veronica Orellana, who lives with her three children in the Rancho Brazos neighborhood, said she heard the warning sirens the same time the tornado hit.

"The alarms were loud so I looked out the window," the 38-year-old said. "It was too late and the tornado was already here. I knew we had to get out of there. Our car was blocked by a fallen tree so we just ran down the street."

Texas Governor Rick Perry said in a statement he was deeply saddened by the deaths and that state officials were assisting affected communities.

The area hit included 61 homes built by Habitat for Humanity, the charity said on its website. Habitat for Humanity uses volunteers to build and repair homes for low-income residents.

Angela Jackson, 47, said her home, which was built by Habitat for Humanity 11 years ago, suffered roof damage and broken windows but was still standing. She said she rode out the storm with her three children in a closet.

"We've had high winds before and hail but nothing like this," Jackson said. "It was a freak storm."

In nearby Parker County, about 14 homes and farms suffered severe roof damage and other structural damage and a few buildings were destroyed, said Parker County Judge Mark Riley. No injuries or deaths were reported.

Preliminary reports showed the NWS issued a tornado warning for Granbury 26 minutes before the twister struck. That is an unusually long lead time as the average warning time is 10 to 12 minutes, the weather service said.

Until Wednesday, the tornado season had been mild after two years of intense activity. Only three people had previously died in tornadoes this year, according to weather service statistics.

The deadliest tornado year in decades was 2011 when 553 people were killed, including 161 by a massive tornado that struck Joplin, Missouri.

In March 2012, at least 39 people were killed in a chain of tornadoes from the Midwest to the Gulf of Mexico. A total of 70 people were killed in tornadoes last year.

The tornado season in the United States typically starts in the Gulf Coast states in late winter, and then moves north with the warming weather, peaking around May and trailing off by July.